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drm/i915/dsi: Use unconditional msleep for the panel_on_delay when there is no reset-deassert MIPI-sequence 

Commit 25b4620ee8 ("drm/i915/dsi: Skip delays for v3 VBTs in vid-mode")
added an intel_dsi_msleep() helper which skips sleeping if the
MIPI-sequences have a version of 3 or newer and the panel is in vid-mode;
and it moved a bunch of msleep-s over to this new helper.

This was based on my reading of the big comment around line 730 which
starts with "Panel enable/disable sequences from the VBT spec.",
where the "v3 video mode seq" column does not have any wait t# entries.

Given that this code has been used on a lot of different devices without
issues until now, it seems that my interpretation of the spec here is
mostly correct.

But now I have encountered one device, an Acer Aspire Switch 10 E
SW3-016, where the panel will not light up unless we do actually honor the
panel_on_delay after exexuting the MIPI_SEQ_PANEL_ON sequence.

What seems to set this model apart is that it is lacking a
MIPI_SEQ_DEASSERT_RESET sequence, which is where the power-on
delay usually happens.

Fix the panel not lighting up on this model by using an unconditional
msleep(panel_on_delay) instead of intel_dsi_msleep() when there is
no MIPI_SEQ_DEASSERT_RESET sequence.

Fixes: 25b4620ee8 ("drm/i915/dsi: Skip delays for v3 VBTs in vid-mode")
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201118124058.26021-1-hdegoede@redhat.com
(cherry picked from commit 6fdb335f1c)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
master
Hans de Goede 2020-11-18 13:40:58 +01:00 committed by Jani Nikula
parent 7c53f6b671
commit 00cb645fd7
1 changed files with 13 additions and 3 deletions
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16
drivers/gpu/drm/i915/display/vlv_dsi.c
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@ -812,10 +812,20 @@ static void intel_dsi_pre_enable(struct intel_atomic_state *state,
intel_dsi_prepare(encoder, pipe_config);
intel_dsi_vbt_exec_sequence(intel_dsi, MIPI_SEQ_POWER_ON);
intel_dsi_msleep(intel_dsi, intel_dsi->panel_on_delay);
/* Deassert reset */
intel_dsi_vbt_exec_sequence(intel_dsi, MIPI_SEQ_DEASSERT_RESET);
/*
* Give the panel time to power-on and then deassert its reset.
* Depending on the VBT MIPI sequences version the deassert-seq
* may contain the necessary delay, intel_dsi_msleep() will skip
* the delay in that case. If there is no deassert-seq, then an
* unconditional msleep is used to give the panel time to power-on.
*/
if (dev_priv->vbt.dsi.sequence[MIPI_SEQ_DEASSERT_RESET]) {
intel_dsi_msleep(intel_dsi, intel_dsi->panel_on_delay);
intel_dsi_vbt_exec_sequence(intel_dsi, MIPI_SEQ_DEASSERT_RESET);
} else {
msleep(intel_dsi->panel_on_delay);
}
if (IS_GEMINILAKE(dev_priv)) {
glk_cold_boot = glk_dsi_enable_io(encoder);